The Drug Enforcement Administration (DEA) has announced the reclassification of hydrocodone combination products from Schedule III to Schedule II under federal law. Schedule II drugs are substances known to be dangerous, prone to abuse, or could lead to severe psychological or physical dependence.

Combination hydrocodone painkiller products were previously regulated as Schedule III products under the law. Schedule III is the DEA category for substances that have accepted medical use, moderate potential for abuse, and the potential for dependency, according to the DEA definition. As a Schedule II substance, hydrocodone combination products will be subject to more stringent prescribing controls, such as bans on refills, Regulatory Affairs Professionals Society (RAPS) reports.

Non-combination hydrocodone drugs are already Schedule II drugs. The new policy will affect some of the country’s most-prescribed painkillers, including Vicodin, RAPS reports. Food and Drug Administration (FDA) figures indicate that hydrocodone combination products were prescribed more than 130 million times in the US in 2011, and that number has likely risen. The FDA, in recommending the change of classification, says it sought to balance the need “to ensure continued access” for patients who rely on continuous pain relief while “addressing the ongoing concerns about abuse and misuse.” The FDA says abuse has reached “epidemic proportions” in certain parts of the United States.

The change will make hydrocodone combination drugs harder to obtain. Some pharmacies do not dispense Schedule II drugs and some states prohibit nurse practitioners and physicians’ assistants from prescribing them, a Los Angeles Times editorial notes. Some say the ban on refills could help prevent addiction by having pain patients see their doctor more frequently. But the Times editorial says the regulation should have a mechanism to monitor painkiller prescriptions so doctors know what drugs the patient has already been prescribed and when.

The reclassification decision is the culmination of a five-year evaluation process begun in 2009.